The present disclosure relates to lithographic methods, and particularly to a method of removing crystalline salts on a substrate primed with a solvent that induces deposition of the crystalline salts.
Primer materials are commonly employed on a semiconductor substrate before spin coating to form an adhesion promoter for a photoresist. An adhesion promoter layer can be formed on the surface of a patterned or unpatterned substrate, which can be a semiconductor substrate, in many different ways. After formation of the adhesion layer, a photoresist is applied and planarized. The photoresist is subsequently lithographically exposed and developed to form a pattern on the substrate.
The thickness of the adhesion promoter formed by various methods known in the art depends on the method of deposition, and is affected by the composition of the underlying material. For example, it has been observed that an undoped silicon surface tends to cause the adhesion promoter to have a thickness of about one atomic monolayer of the adhesion promoter material, while a silicon surface doped with phosphorus tends to cause the adhesion promoter layer to have a thickness of several atomic monolayers of the adhesion promoter layer.